阅读说明：本技术 双偏振雷达标定方法及系统 (Dual-polarization radar calibration method and system ) 是由 虞海峰 孙召平 王京 钟涛 杜云东 张亚斌 王晓科 于 2021-02-10 设计创作，主要内容包括：本申请实施例公开了一种双偏振雷达标定方法及系统,在双偏振雷达的每次平面扫描结束时,控制标定信号源产生射频信号,射频信号的频率与双偏振雷达的工作频率相同；将射频信号分成相同的两路目标信号；将两路目标信号分别注入双偏振雷达的两路接收通道；获取两路接收通道输出的信号的第一差异；在双偏振雷达的每次体积扫描结束时,根据该次体积扫描过程中获取的多个第一差异以及预置的基准差异,确定双偏振雷达是否异常。本申请实施例提供的方案,在每相邻两次平面扫描之间进行一次标定,然后利用一次体积扫描过程中确定的多个第一差异确定双偏振雷达是否异常,在不影响雷达业务运行的情况下,保证双偏振雷达标定的精准度和时效性。(The embodiment of the application discloses a dual-polarization radar calibration method and a dual-polarization radar calibration system, wherein a calibration signal source is controlled to generate a radio frequency signal when each plane scanning of a dual-polarization radar is finished, and the frequency of the radio frequency signal is the same as the working frequency of the dual-polarization radar; dividing the radio frequency signal into two paths of same target signals; injecting two paths of target signals into two paths of receiving channels of a dual-polarization radar respectively; acquiring a first difference of signals output by two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference. According to the scheme provided by the embodiment of the application, once calibration is carried out between every two adjacent planar scanning, whether the dual-polarization radar is abnormal or not is determined by utilizing a plurality of first differences determined in the process of once volume scanning, and the calibration accuracy and the timeliness of the dual-polarization radar are guaranteed under the condition that the operation of radar services is not influenced.)

1. A dual polarization radar calibration method is characterized by comprising the following steps:

when each plane scanning of the dual-polarization radar is finished, controlling a calibration signal source to output a radio frequency signal, wherein the frequency of the radio frequency signal is the same as the working central frequency of the dual-polarization radar;

dividing the radio frequency signal into two identical target signals;

injecting the two paths of target signals into two paths of receiving channels of the dual-polarization radar respectively;

acquiring a first difference of signals output by the two receiving channels;

and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal or not according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

2. The method of claim 1, wherein controlling the calibration signal source to output the rf signal comprises:

and sending a control instruction to a high-speed switch in the calibration signal source to enable the high-speed switch to supply power to an output path switch of the radio-frequency signal so as to open the output path of the radio-frequency signal.

3. The method of claim 2, further comprising:

and before the next plane scanning of the dual-polarization radar is started, stopping sending a control instruction to the high-speed switch of the calibration signal source so as to cut off an output channel of the calibration signal source.

4. The method according to claim 1, wherein the injecting the two target signals into two receiving channels of the dual-polarization radar respectively comprises:

inputting each path of target signal to the one-to-one corresponding directional coupler through a fixed-amplitude and phase-stable cable;

each directional coupler inputs a target signal to a corresponding receiving channel.

5. The method according to claim 1, wherein the first difference of the signals output by the two receiving channels is a difference of amplitudes and/or a difference of phases of the signals output by the two receiving channels.

6. The method according to any one of claims 1 to 5, wherein the determining whether the dual polarization radar is abnormal according to the plurality of first differences acquired during the volume scanning and a preset reference difference comprises:

calculating the difference value of each first difference and the reference difference to obtain a calculation result;

if the calculation result represents that each first difference is consistent with the reference difference, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

7. The method of claim 6, further comprising:

if the calculation result represents that each first difference is inconsistent with the reference difference and the difference value of each first difference and the reference difference is within a preset range, determining a deviation value according to the difference value of each first difference and the reference difference; correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value;

and if the calculation result represents that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not in a preset range, outputting alarm information.

8. A dual polarization radar calibration system, comprising: calibrating a signal source, a control terminal and a dual-polarization radar receiving system; wherein the content of the first and second substances,

the control terminal is used for controlling the calibration signal source to output a radio frequency signal when each plane scanning of the dual-polarization radar is finished, and the frequency of the radio frequency signal is the same as the working central frequency of the dual-polarization radar;

the calibration signal source is also used for dividing the radio frequency signal into two paths of same target signals; injecting the two paths of target signals into two paths of receiving channels of the dual-polarization radar receiving system respectively;

the dual-polarization radar receiving system is used for acquiring a first difference of signals output by the two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal or not according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

9. The system according to claim 8, wherein the control terminal, when controlling the calibration signal source to output the radio frequency signal, is specifically configured to:

and sending a control instruction to a high-speed switch in the calibration signal source to enable the high-speed switch to supply power to an output path switch of the radio-frequency signal so as to open the output path of the radio-frequency signal.

10. The system of claim 8, further comprising: the two directional couplers are connected with the calibration signal source through an amplitude and phase stabilizing cable, and each directional coupler is connected to one receiving channel of the dual-polarization radar receiving system;

and injecting each path of target signal into two paths of receiving channels of the dual-polarization radar receiving system through the directional couplers corresponding to one path of target signal.

11. The system according to any one of claims 8 to 10, wherein the dual polarization radar receiving system is configured to determine whether the dual polarization radar is abnormal according to a plurality of first differences acquired during the volume scanning and a preset reference difference, and is specifically configured to:

calculating the difference value of each first difference and the reference difference to obtain a calculation result;

if the calculation result represents that each first difference is consistent with the reference difference, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

12. The method of claim 11, wherein the dual polarization radar receiving system is further configured to:

if the calculation result represents that each first difference is inconsistent with the reference difference and the difference value of each first difference and the reference difference is within a preset range, determining a deviation value according to the difference value of each first difference and the reference difference; correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value;

and if the calculation result represents that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not in a preset range, outputting alarm information through the control terminal.

Technical Field

The application relates to the technical field of radars, in particular to a dual-polarization radar calibration method and system.

Background

At present, the dual-polarization radar in China is converted from trial operation to business operation, and the number of the dual-polarization radar in a new generation weather radar network is increased year by year. The dual polarization radar can transmit and receive both horizontally polarized waves and vertically polarized waves. The technicians can perform service research such as precipitation estimation based on the difference between the horizontally polarized wave and the vertically polarized wave.

In practical applications, the horizontally polarized wave is received through a horizontal receiving channel in the dual-polarization radar, and the vertically polarized wave is received through a vertical receiving channel in the dual-polarization radar. Normally, due to the difference of the two transmission channels (i.e. the horizontal receiving channel and the vertical receiving channel), a certain deviation exists between the difference of the polarized waves output by the two receiving channels and the difference of the polarized waves input into the two transmission channels, which is allowed. However, when the dual-polarization radar system is abnormal, the deviation between the difference between the polarized waves output by the two receiving channels and the difference between the polarized waves input into the two transmitting channels is increased, which affects the accuracy of the service research result. Therefore, it is necessary to calibrate the dual polarization radar to monitor whether the dual polarization radar system is abnormal.

Disclosure of Invention

The application aims to provide a dual-polarization radar calibration method and a system, and the method comprises the following technical scheme:

a dual-polarization radar calibration method comprises the following steps:

when each plane scanning of the dual-polarization radar is finished, controlling a calibration signal source to output a radio frequency signal, wherein the frequency of the radio frequency signal is the same as the working central frequency of the dual-polarization radar;

dividing the radio frequency signal into two identical target signals;

injecting the two paths of target signals into two paths of receiving channels of the dual-polarization radar respectively;

acquiring a first difference of signals output by the two receiving channels;

and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal or not according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

Preferably, the method for controlling the calibration signal source to output the radio frequency signal includes:

and sending a control instruction to a high-speed switch in the calibration signal source to enable the high-speed switch to supply power to an output path switch of the radio-frequency signal so as to open the output path of the radio-frequency signal.

The above method, preferably, further comprises:

and before the next plane scanning of the dual-polarization radar is started, stopping sending a control instruction to the high-speed switch of the calibration signal source so as to cut off an output channel of the calibration signal source.

Preferably, the injecting the two target signals into the two receiving channels of the dual-polarization radar respectively includes:

inputting each path of target signal to the one-to-one corresponding directional coupler through a fixed-amplitude and phase-stable cable;

each directional coupler inputs a target signal to a corresponding receiving channel.

In the method, preferably, the first difference between the signals output by the two receiving channels is a difference between amplitudes and/or a difference between phases of the signals output by the two receiving channels.

Preferably, the determining whether the dual-polarization radar is abnormal according to the plurality of first differences acquired in the volume scanning process and a preset reference difference includes:

calculating the difference value of each first difference and the reference difference to obtain a calculation result;

if the calculation result represents that each first difference is consistent with the reference difference, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

The above method, preferably, further comprises:

if the calculation result represents that each first difference is inconsistent with the reference difference and the difference value of each first difference and the reference difference is within a preset range, determining a deviation value according to the difference value of each first difference and the reference difference; correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value;

and if the calculation result represents that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not in a preset range, outputting alarm information.

A dual-polarization radar calibration system, comprising: calibrating a signal source, a control terminal and a dual-polarization radar receiving system; wherein the content of the first and second substances,

the control terminal is used for controlling the calibration signal source to output a radio frequency signal when each plane scanning of the dual-polarization radar is finished, and the frequency of the radio frequency signal is the same as the working central frequency of the dual-polarization radar;

the calibration signal source is also used for dividing the radio frequency signal into two paths of same target signals; injecting the two paths of target signals into two paths of receiving channels of the dual-polarization radar receiving system respectively;

the dual-polarization radar receiving system is used for acquiring a first difference of signals output by the two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal or not according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

Preferably, when the control terminal controls the calibration signal source to output the radio frequency signal, the system is specifically configured to:

and sending a control instruction to a high-speed switch in the calibration signal source to enable the high-speed switch to supply power to an output path switch of the radio-frequency signal so as to open the output path of the radio-frequency signal.

The above system, preferably, further comprises: the two directional couplers are connected with the calibration signal source through an amplitude and phase stabilizing cable, and each directional coupler is connected to one receiving channel of the dual-polarization radar receiving system;

and injecting each path of target signal into two paths of receiving channels of the dual-polarization radar receiving system through the directional couplers corresponding to one path of target signal.

Preferably, in the above system, when the dual-polarization radar receiving system determines whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference, the dual-polarization radar receiving system is specifically configured to:

calculating the difference value of each first difference and the reference difference to obtain a calculation result;

if the calculation result represents that each first difference is consistent with the reference difference, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

The above system, preferably, the dual polarization radar receiving system is further configured to:

if the calculation result represents that each first difference is inconsistent with the reference difference and the difference value of each first difference and the reference difference is within a preset range, determining a deviation value according to the difference value of each first difference and the reference difference; correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value;

and if the calculation result represents that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not in a preset range, outputting alarm information through the control terminal.

According to the scheme, the calibration method and the calibration system for the dual-polarization radar control the calibration signal source to generate the radio frequency signal when each plane scanning of the dual-polarization radar is finished, wherein the frequency of the radio frequency signal is the same as the working frequency of the dual-polarization radar; dividing the radio frequency signal into two paths of same target signals; injecting two paths of target signals into two paths of receiving channels of a dual-polarization radar respectively; acquiring a first difference of signals output by two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference. According to the scheme provided by the embodiment of the application, once calibration is carried out between every two adjacent planar scanning, whether the dual-polarization radar is abnormal or not is determined by utilizing a plurality of first differences determined in the process of once volume scanning, and the calibration accuracy and the timeliness of the dual-polarization radar are guaranteed under the condition that the operation of radar services is not influenced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a flowchart of an implementation of a dual polarization radar calibration method according to an embodiment of the present disclosure;

fig. 2 is a diagram illustrating an exemplary connection relationship between a high-speed switch of a calibration signal source and an output path switch of a radio frequency signal according to an embodiment of the present application;

FIG. 3 is a diagram illustrating a dual polarization radar after being modified by the calibration technique provided in the embodiment of the present application;

fig. 4 is an exemplary diagram illustrating that the difference value between each first difference and the reference difference is not within a preset range according to the embodiment of the present application;

FIG. 5 is an exemplary diagram of a design interface for a reference difference corresponding to a magnitude difference provided by an embodiment of the present application;

FIG. 6 is an exemplary diagram of a calibration signal source function turn-on and turn-off configuration interface provided by an embodiment of the present application;

FIG. 7 is an exemplary diagram of a configuration interface for operating logic of different manners of calibrating a signal source provided by an embodiment of the present application;

fig. 8 is a schematic structural diagram of a dual polarization radar calibration system according to an embodiment of the present application;

fig. 9 is a schematic internal structural diagram of a calibration signal source according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a housing of a calibration signal source according to an embodiment of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other sequences than described or illustrated herein.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without inventive step, are within the scope of the present disclosure.

Signals received by the radar can be divided into a test signal and an echo signal according to the action, wherein the test signal is used for checking or calibrating the radar system, and the echo signal is a working signal of the radar and is used for checking information such as amplitude, direction, speed and the like of a target object. The dual-polarization radar calibration method provided by the embodiment of the application calibrates the test signal and the echo signal only one at the same time, but not simultaneously, or otherwise confusion occurs, by using a time period (namely, an instant of elevation angle elevation and a time period before the next volume scanning starts after one volume scanning is finished) during which the radar system neither transmits nor receives.

As shown in fig. 1, an implementation flowchart of a dual polarization radar calibration method provided in the embodiment of the present application may include:

step 101: and when each plane scanning of the dual-polarization radar is finished, controlling the calibration signal source to output a radio frequency signal, wherein the frequency of the radio frequency signal is the same as the working central frequency of the dual-polarization radar.

When the dual-polarization radar scans, the volume scanning is performed circularly, namely, after one volume scanning is completed, the next volume scanning is performed. Each time of volume scanning is composed of multiple times of plane scanning, each time of plane scanning is performed at a specific elevation angle, the elevation angles of different plane scanning are different, each time of plane scanning is completed, elevation angle adjustment is performed, and the next time of plane scanning is performed after the elevation angle is adjusted until one time of volume scanning is completed. Typically, the time required to perform one volume scan is 6 minutes, while the time required to perform one planar scan is 30 seconds.

Therefore, in the embodiment of the present application, the calibration is performed by using the time of the elevation angle (i.e. adjusting the elevation angle) of the radar, which is equivalent to performing calibration once every 30 seconds on two receiving channels of the dual-polarization radar.

In the embodiment of the application, the calibration signal source is controlled to be opened and closed by the control terminal installed in the radar equipment room, the control instruction is sent out by the control software, and the control signal is finally sent to the calibration signal source installed in the antenna housing through interface conversion and optical fiber transmission. When the calibration signal source is turned on, the radio frequency signal is output, and when the calibration signal source is turned off, the radio frequency signal is not output. Interference brought by transmission can be reduced through optical fiber transmission, and the reliability of control instruction transmission is ensured. Optionally, in order to reduce the environmental electromagnetic interference, the control command may be transmitted in a manner of two differential signals. In order to avoid the signal source to produce interfering signal in the radar operation and influence the data quality of radar, this application embodiment, will mark the signal source and install in the antenna house.

In addition, in order to improve the environmental temperature adaptability of the calibration signal source, for example, the calibration signal source can stably work in the range of-20 ℃ to +50 ℃, a temperature compensation circuit can be designed in the calibration signal source to cope with a low-temperature environment, and a refrigeration fan can be installed to cope with a high-temperature environment.

Optionally, the calibration signal source may be a signal source with a compilable output frequency, so that through the compilation, the calibration signal source can generate radio frequency signals with different frequencies, so as to be suitable for radar systems with different frequency points.

Step 102: the rf signal is divided into two identical signals (for convenience of description, referred to as target signals).

Alternatively, a two-way power divider may be used to divide the rf signal into two identical signal target signals.

Optionally, a multi-path power divider may be used to divide the radio frequency signal into multiple paths of identical signals, and two paths of signals are taken as target signals.

Optionally, in order to avoid the influence of the high-power radio-frequency signal during the operation of the radar on or damage the calibration signal source, an isolator may be disposed inside the calibration signal source, and the radio-frequency signal is input to the isolator first, and then the isolator inputs the radio-frequency signal to the power divider. In order to further improve the isolation of the calibration signal source to the high-power radio-frequency signals in the radar operation, an electromagnetic shielding design can be made on the shell of the calibration signal source.

Wherein the frequency of the target signal is the same as the central frequency of the dual-polarization radar.

Step 103: and respectively injecting the two paths of target signals into two receiving channels of the dual-polarization radar. These two receive channels are generally referred to as a horizontal channel and a vertical channel.

Step 104: and acquiring a first difference of signals output by the two receiving channels. The first difference may be a difference between amplitudes of the signals output by the two receiving channels, or may be a difference between phases of the signals output by the two receiving channels, or may include a difference between the amplitudes of the signals output by the two receiving channels and a difference between the phases of the signals output by the two receiving channels.

Step 105: and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

The reference difference is the difference of signals output by two receiving channels of the dual-polarization radar after the radio frequency signals are divided into two identical target signals and the two target signals are respectively injected into the two receiving channels of the dual-polarization radar. The working state of the dual-polarization radar after being installed and tested to be put into use is usually normal, therefore, when the dual-polarization radar is just installed and tested to be put into use, a calibration signal source is controlled to generate radio frequency signals, the radio frequency signals are divided into two paths of same target signals, the two paths of target signals are respectively injected into two paths of receiving channels of the dual-polarization radar, and then the difference of signals output by the two paths of receiving channels is used as reference difference.

As can be seen from the foregoing, the time required for a volume scan of the radar is generally 6 minutes, while the time required for a plane scan is 30 seconds, so that 12 first differences are obtained during one submit scan. In some cases, the radar system changes the operation mode, at this time, the volume scanning mode changes, and after the volume scanning mode is changed, the time required for one volume scanning and the number of times of plane scanning are correspondingly adjusted.

According to the dual-polarization radar calibration method provided by the embodiment of the application, when each plane scanning of the dual-polarization radar is finished, a calibration signal source is controlled to generate a radio frequency signal, and the frequency of the radio frequency signal is the same as the working frequency of the dual-polarization radar; dividing the radio frequency signal into two paths of same target signals; injecting two paths of target signals into two paths of receiving channels of a dual-polarization radar respectively; acquiring a first difference of signals output by two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference. According to the scheme provided by the embodiment of the application, once calibration is carried out between every two adjacent planar scanning, whether the dual-polarization radar is abnormal or not is determined by utilizing a plurality of first differences determined in the process of once volume scanning, and the calibration accuracy and the timeliness of the dual-polarization radar are guaranteed under the condition that the operation of radar services is not influenced. On the premise of not influencing service operation, the consistency of the amplitude and the phase of the receiving channel of the dual-polarization radar is automatically calibrated on line so as to improve the calibration precision and the timeliness of the dual-polarization radar, improve the data quality of the dual-polarization radar and better play the role of the dual-polarization radar.

In the process of implementing the present application, the inventor finds that, when the calibration signal source is controlled to output the radio frequency signal, if the following method is implemented:

and controlling a power supply of the calibration signal source to supply power to the calibration signal source so as to start the calibration signal source, so that the calibration signal source generates radio frequency signals. And before the next plane scanning of the dual-polarization radar starts, controlling a power supply of the calibration signal source to stop supplying power to the calibration signal source so as to close the calibration signal source, so that the calibration signal source does not generate radio frequency signals any more.

Although the isolation of the calibration signal source (i.e. the power difference between the calibration signal source when the radio frequency switch is turned on and off) can reach more than 80dB by the control method, the use requirement cannot be met, and the radar bottom noise is influenced.

In order to improve the isolation of the calibration signal source, in an optional embodiment, an implementation manner of controlling the calibration signal source to output the radio frequency signal provided in the embodiment of the present application may be:

and sending a control instruction to a high-speed switch in the calibration signal source to enable the high-speed switch to supply power to an output path switch of the radio-frequency signal in the radio-frequency signal source so as to open an output path of the radio-frequency signal.

Alternatively, the high-speed switch may be implemented based on a transistor, for example, the high-speed switch may include an NPN transistor and a PNP transistor. Fig. 2 is a diagram illustrating a connection relationship between a high-speed switch of a calibration signal source (not shown in the figure) and an output path switch of an rf signal according to an embodiment of the present application. In the case of the example shown in the figure,

the main devices of the high-speed switch comprise an NPN type triode V1 and a PNP type triode V2 and a +5V direct current power supply, and other devices of the high-speed switch are used for being matched with the NPN type triode V1 and the PNP type triode V2, so that the output path of the high-speed switch for generating radio frequency signals is the voltage required by the work of the switch U6. Therefore, the structure of the high-speed switch in the embodiment of the present application is not limited to the structure shown in fig. 2, and other structures are also possible as long as the voltage required for the output path switch U6, which enables the high-speed switch to generate the radio frequency signal, to operate. The radio frequency signal generated by the calibration signal source is output through the U6, that is, the output path of the radio frequency signal generated by the calibration signal source is the branch where the U6 is located. The input end of the U6 is a No. 2 pin V-TUNE which is connected with the output of the calibration signal source, the output end of the U6 is a No. 10 pin RF-OUT, the U6 is turned on after the No. 14 pin VCC is powered on, and then the U6 is turned on, so that the radio frequency signal generated by the calibration signal source is input into the U6 through the No. 2 pin V-TUNE of the U6 and then is output through the No. 10 pin RF-OUT of the U6. The output path switch U6 may be a voltage controlled oscillator.

In this embodiment, the control command sent to the high-speed switch may be an analog signal that makes the high-speed switch tube conductive and has a predetermined level. The high-speed switch is turned on after receiving the control command, so that the high-speed switch supplies power to the U6, that is, the output of the high-speed switch, that is, the output of the collector of the triode V2 is connected with the No. 14 pin VCC of the U6, so that the U6 is turned on, and the radio frequency signal output by the calibration signal source is output through the U6.

The time of elevation angle lifting in the radar operation is usually shorter, the time of leaving for calibration is within 1 second, in order to guarantee the timeliness of calibration, the calibration signal source is always powered on and generates radio frequency signals, the high-speed switch is used for controlling the opening and closing of an output channel of the calibration signal source, the radio frequency signals are stably output when the calibration signal source is powered on, and no output is realized quickly when the power is off. The isolation of the calibration signal source is improved, the isolation is over 100dB, and the noise of the calibration signal source is far lower than the sensitivity of a radar system.

In an alternative embodiment, before the next planar scanning of the dual-polarization radar starts, the sending of the control instruction to the high-speed switch of the calibration signal source is stopped, so as to turn off the output path of the radio-frequency signal generated by the calibration signal source. At this time, the calibration signal source still generates the rf signal, but the rf signal cannot be output through the output path due to the closing of the output path.

In an optional embodiment, an implementation manner of injecting the two target signals into the two receiving channels of the dual-polarization radar respectively may be:

inputting each path of target signal to the one-to-one corresponding directional coupler through a fixed-amplitude and phase-stable cable;

each directional coupler inputs a target signal to a corresponding receiving channel.

That is to say, in the embodiment of the present application, the calibration signal source has two signal output interfaces, each output interface is connected to one directional coupler, and each directional coupler is connected to one receiving channel of the dual-polarization radar.

In an optional embodiment, one implementation manner of determining whether the dual polarization radar is abnormal according to the plurality of first differences acquired during the volume scanning and the preset reference difference may be:

and calculating the difference value of each first difference and the reference difference to obtain a calculation result.

If the calculation result indicates that all the first differences are consistent with the reference differences, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

In the embodiment of the present application, for each first difference, if the absolute value of the difference between the first difference and the reference difference is smaller than a first threshold, it indicates that the first difference is consistent with the reference difference, otherwise, it indicates that the first difference is inconsistent with the reference difference. As an example, the first threshold may be 0.01dB corresponding to the amplitude difference; the first threshold may be 0.1 ° corresponding to the phase difference.

Further, if the calculation result indicates that each first difference is inconsistent with the reference difference and the difference value between each first difference and the reference difference is within a preset range, for example, the absolute value of the difference value between each first difference and the reference difference is between a first threshold and a second threshold, determining a deviation value according to the difference value between each first difference and the reference difference; and correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value. The second threshold is greater than the first threshold. As an example, the second threshold may be 0.2dB corresponding to the amplitude difference; the second threshold may be 0.6 ° corresponding to the phase difference.

In the embodiment of the application, if the difference value between each first difference and the reference difference is within the preset range, it indicates that the radar system is changed and needs to be revised. Optionally, a mean value or a median value of difference values between each first difference and the reference difference may be used as a deviation value, and the difference of the polarized waves output by the two receiving channels in the next volume scanning process is adjusted in the opposite direction according to the deviation value. For example,

taking the difference between the signals output by the two receiving channels as the amplitude difference between the signal output by the horizontal channel and the signal output by the vertical channel as an example, assuming that the reference difference between the signal output by the horizontal channel and the signal output by the vertical channel is 0.5dB, and the calculated deviation value is 0.15dB, that is, in the actual scanning process, the difference between the signal output by the horizontal channel and the signal output by the vertical channel is 0.15dB higher than the reference difference, in the next volume scanning process, the difference between the polarized waves output by the two receiving channels is reduced by 0.15dB, and the difference between the signal output by the horizontal channel and the signal output by the vertical channel after the reduction by 0.15dB is output to the user. And if the calculated deviation value is-0.15 dB, that is, in the actual scanning process, the difference between the signal output by the horizontal channel and the signal output by the vertical channel is 0.15dB lower than the reference difference, in the next volume scanning process, the difference between the polarized waves output by the two receiving channels needs to be increased by 0.15dB, and the difference between the signal output by the horizontal channel and the signal output by the vertical channel after the increase by 0.15dB is output to the user. As shown in fig. 3, it is obvious that the maximum variation range of the amplitude difference between two channels after the calibration technique provided by the embodiment of the present application is used for a dual-polarization radar corrected by using the calibration technique provided by the embodiment of the present application is 0.07dB, which meets the requirement of the technical index not greater than 0.2dB, and the radar difference at the corresponding time is normal, which meets the requirement of service observation.

And if the calculation result represents that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not in the preset range, for example, the absolute values of the difference values of all the first differences and the reference differences are greater than a second threshold value, outputting alarm information to remind a radar operator that the radar needs to be maintained or repaired. As shown in fig. 4, an exemplary diagram that the difference between each first difference and the reference difference provided for the embodiment of the present application is not within a preset range is provided, in this example, the maximum variation range of the amplitude difference between the two channels is 6.5dB, and exceeds a set threshold range, so that no revision is performed, but an alarm message is generated to prompt a radar operator that the radar system needs to be maintained or repaired, so as to avoid that abnormal data enters a service radar network and affects the judgment of a forecaster. And (4) timely feeding the fault back to radar operators through alarm information, and after the fault spare part is replaced, enabling the radar calibration result to be normal and putting the radar into service operation again.

Further, in the embodiment of the present application, the reference difference may be set by a user, as shown in fig. 5, which is an exemplary diagram of a design interface of the reference difference corresponding to the amplitude difference provided in the embodiment of the present application. In this interface, the user may enter the base difference in the input box after the "SP 14 TS ZDR reference value".

Further, the embodiment of the present application further adds a configuration function for the calibration signal source, which specifically may be: the calibration signal source function can be conveniently controlled to be turned on and off by a user through the configuration file, or control logics in different modes can be realized. Fig. 6 is a diagram illustrating an exemplary configuration interface for turning on and off the calibration signal source function according to an embodiment of the present application. In this interface, ts _ enable is given different values to control the calibration signal source function to be turned on or off, for example, ts _ enable is equal to 1, which indicates that the calibration signal source function is to be controlled to be turned on, ts _ enable is equal to 0, which indicates that the calibration signal source function is to be controlled to be turned off. The dual-polarization radar calibration method provided by the embodiment of the application can be executed only when the function of the calibration signal source is started.

Fig. 7 is a diagram illustrating an example of a configuration interface of working logic of different modes for calibrating a signal source according to an embodiment of the present application. The control logic for calibrating the signal source is divided into two types: a continuous wave control mode and a pulse control mode; the continuous wave control mode is to control the calibration signal source to output a continuous wave radio frequency signal at a specified time point, and is used for calibrating the amplitude and phase consistency of the two receiving channels. The pulse control mode refers to controlling the output width and the output time sequence position of the pulse, and can realize calibration under each radar emission pulse. The radar system in operation at present is calibrated by default in a continuous wave control mode. In fig. 7, tswlTrgPos is 64, and tswltrghen is 0, and it indicates that the operation mode of the calibration signal source is the continuous wave control mode.

In conclusion, the proportion of the dual-polarization radar in the new-generation weather radar network in China is higher, the data quality requirement of the dual-polarization radar is obviously higher than that of the single-polarization radar, in order to meet the automatic online inspection and online correction of the core technical indexes of the dual-polarization radar and ensure the precision and accuracy of the data of the dual-polarization radar, the calibration signal source and the calibration technology of the application are provided, the consistency of the amplitude and the phase of the receiving channel of the dual-polarization radar is calibrated online, the dual-polarization radar is ensured to operate in the technical index range of which the amplitude difference is not more than 0.2dB and the phase difference is not more than 3 degrees, a calibration system can automatically correct the data with small calibration deviation, the unqualified dual-polarization radar products are prevented from being used in a service system, and meanwhile, an alarm signal is generated to inform a radar operation technician in time in case of urgent maintenance when the calibration result seriously exceeds, the method avoids the influence of the data quality problem of the radar system on the accurate prediction of a forecaster and the wrong decision of decision departments such as flood prevention and disaster resistance.

The invention and the service application of the calibration signal source and the calibration technology better play the technical advantages of the dual-polarization radar in quantitative precipitation estimation, precipitation type classification and the like, and better play the important role of the dual-polarization radar in disaster prevention and reduction.

Corresponding to the method embodiment, an embodiment of the present application further provides a dual polarization radar calibration system, and a schematic structural diagram of the dual polarization radar calibration system provided in the embodiment of the present application is shown in fig. 8, and may include:

a calibration signal source 801, a control terminal 802 and a dual-polarization radar receiving system 803; wherein the content of the first and second substances,

the control terminal 802 is configured to control the calibration signal source 801 to output a radio frequency signal when each plane scanning of the dual-polarization radar is finished, where the frequency of the radio frequency signal is the same as the working center frequency of the dual-polarization radar. The control terminal 802 may send a control instruction to the calibration signal source through the signal processor of the dual-polarization radar receiving system 803, so as to control the calibration signal source 801 to output a radio frequency signal. I.e. the control signal generated by the control terminal 802 is forwarded to the calibration signal source 801 via the signal processor. And in the time period of normal operation of the radar system, the dual-polarization radar receiving system is used for transmitting or receiving and relevant processing of the normal operation signal of the radar system.

Optionally, the control terminal 802 may be an upper computer, or may be a mobile communication terminal, such as a smart phone.

The calibration signal source 801 is further configured to divide the radio frequency signal into two identical target signals; injecting two paths of target signals into two paths of receiving channels of a dual-polarization radar receiving system 803 respectively; these two receive channels are generally referred to as a horizontal channel and a vertical channel.

The dual-polarization radar receiving system 803 is configured to obtain, through the signal processor, a first difference between signals output by the two receiving channels; the first difference may be a difference between amplitudes of the signals output by the two receiving channels, or may be a difference between phases of the signals output by the two receiving channels, or may include a difference between the amplitudes of the signals output by the two receiving channels and a difference between the phases of the signals output by the two receiving channels. And when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal or not through a signal processor according to a plurality of first differences acquired in the volume scanning process and a preset reference difference.

According to the dual-polarization radar calibration system provided by the embodiment of the application, when each plane scanning of the dual-polarization radar is finished, the calibration signal source is controlled to generate the radio frequency signal, and the frequency of the radio frequency signal is the same as the working frequency of the dual-polarization radar; dividing the radio frequency signal into two paths of same target signals; injecting two paths of target signals into two paths of receiving channels of a dual-polarization radar respectively; acquiring a first difference of signals output by two receiving channels; and when each volume scanning of the dual-polarization radar is finished, determining whether the dual-polarization radar is abnormal according to a plurality of first differences acquired in the volume scanning process and a preset reference difference. According to the scheme provided by the embodiment of the application, once calibration is carried out between every two adjacent planar scanning, whether the dual-polarization radar is abnormal or not is determined by utilizing a plurality of first differences determined in the process of once volume scanning, and the calibration accuracy and the timeliness of the dual-polarization radar are guaranteed under the condition that the operation of radar services is not influenced. On the premise of not influencing service operation, the consistency of the amplitude and the phase of the receiving channel of the dual-polarization radar is automatically calibrated on line so as to improve the calibration precision and the timeliness of the dual-polarization radar, improve the data quality of the dual-polarization radar and better play the role of the dual-polarization radar.

In an alternative embodiment, one of the two target signals output by the calibration signal source 801 is input to the horizontal channel through one directional coupler, and the other target signal is input to the vertical channel through the other directional coupler. The calibration signal source 801 is connected with the coupler through an amplitude-stabilizing phase-stabilizing cable. The lengths of the amplitude-stabilizing phase-stabilizing cables connecting the two directional couplers are equal.

In an alternative embodiment, an internal structural schematic diagram of the calibration signal source provided in the embodiment of the present application is shown in fig. 9, and may include:

a programmable signal source 901 and a power divider 902; wherein the content of the first and second substances,

the programmable signal source 901 is used to generate a radio frequency signal. The output frequency of the programmable signal source 901 can be compiled, so that the programmable signal source 901 can generate radio frequency signals with different frequencies through compiling, and the programmable signal source is suitable for radar systems with different frequency points.

The power divider 902 may be a two-way power divider or a multi-way power divider.

Preferably, in order to avoid the influence or damage of the calibration signal source by the high-power radio frequency signal during the radar operation, the calibration signal source may further include an isolator 903.

In an optional embodiment, in order to further improve the isolation of the calibration signal source to the high-power radio-frequency signal in the radar operation, an electromagnetic shielding design may be further made on the housing of the calibration signal source. As shown in fig. 10, which is a schematic structural diagram of a housing of a calibration signal source provided in the embodiment of the present application, in the exemplary diagram, two output interfaces J1 and J2 are used for outputting two target signals, and an XS3 interface is used for receiving a control command sent by the control terminal 802.

In an alternative embodiment, the control terminal 802 may send a control instruction to a high-speed switch in the programmable signal source 901 through a signal processor of the dual-polarization radar receiving system 803, so that the high-speed switch supplies power to an output path switch of the radio frequency signal, so as to open an output path of the radio frequency signal generated by the programmable signal source 901, where the output path is used for outputting the radio frequency signal generated by the programmable signal source 901.

In an alternative embodiment, before the next planar scanning of the dual polarization radar starts, the control terminal 802 stops sending the control instruction to the high-speed switch of the calibration signal source 801 to turn off the output path of the radio frequency signal generated by the calibration signal source 801.

In an alternative embodiment, the dual-polarization radar receiving system 803 (mainly a signal processor) determines whether the dual-polarization radar is abnormal according to the plurality of first differences acquired during the volume scanning and a preset reference difference, and is specifically configured to:

and calculating the difference value of each first difference and the reference difference to obtain a calculation result.

If the calculation result indicates that all the first differences are consistent with the reference differences, determining that the dual-polarization radar is normal; otherwise, determining that the dual-polarization radar is abnormal.

In an alternative embodiment, dual polarization radar receiving system 803 (primarily signal processor) is further configured to:

if the calculation result represents that all the first differences are inconsistent with the reference difference and the difference value of all the first differences and the reference difference is within the preset range, determining a deviation value according to the difference value of all the first differences and the reference difference; and correcting the difference of the polarized waves output by the two receiving channels in the next volume scanning process according to the deviation value.

If the calculation result indicates that all the first differences are inconsistent with the reference differences and the difference values of all the first differences and the reference differences are not within the preset range, alarm information is output through the control terminal 802.

In an alternative embodiment, dual polarization radar receiving system 803 (primarily a signal processor) may also be used to:

the configuration interface is output through the control terminal 802, for example, a design interface for outputting the reference difference, so that a user can set the reference difference, or output a configuration interface for turning on and off the function of the calibration signal source, or output a configuration interface for working logic of different modes of the calibration signal source, and so on.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

It should be understood that the technical problems can be solved by combining and combining the features of the embodiments from the claims.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.